Micromorphology of an Upper Paleolithic cultural layer at Grub-Kranawetberg, Austria

Cultural layers are a fundamental part of open-air loess sites. As complex representations of the interaction between human activity and natural processes, we believe these layers deserve detailed investigation. In this paper we consider the impact of hunter-gatherers on sediments and soil formation and present a small-scale, micromorphological study of a cultural layer at Grub-Kranawetberg. Grub-Kranawetberg is a Gravettian site located on a flat crest overlooking the Morava river valley in Lower Austria. We used micromorphology to study the formation of the main cultural layer of the site as well as the bordering underlying and overlying deposits. The studied cultural layer of Grub-Kranawetberg shows evidence of 1) substantial anthropogenic input of organic and mineral material, 2) bioturbation by a diverse soil fauna including mollusks and earthworms, 3) translocation of carbonates, indicating soil-forming processes, 4) trampling and 5) a preserved, though bioturbated, occupation surface without signs of erosion or redeposition. By enhancing nutrient availability and soil faunal activity, the human waste influenced the diversity and composition of the plant communities. We argue that the cultural layer is best described as an anthropogenic soil, indicating that anthropogenic waste already played a role in Late Pleistocene human landscape modification.